[dpdk-dev] Memory leak when adding/removing vhost_user ports

[Yuanhan Liu]

On Mon, Apr 18, 2016 at 10:46:50AM -0700, Yuanhan Liu wrote:
> On Mon, Apr 18, 2016 at 07:18:05PM +0200, Christian Ehrhardt wrote:
> > I assume there is a leak somewhere on adding/removing vhost_user ports.
> > Although it could also be "only" a fragmentation issue.
> > 
> > Reproduction is easy:
> > I set up a pair of nicely working OVS-DPDK connected KVM Guests.
> > Then in a loop I
> >    - add up to more 512 ports
> >    - test connectivity between the two guests
> >    - remove up to 512 ports
> > 
> > Depending on memory and the amount of multiqueue/rxq I use it seems to
> > slightly change when exactly it breaks. But for my default setup of 4
> > queues and 5G Hugepages initialized by DPDK it always breaks at the sixth
> > iteration.
> > Here a link to the stack trace indicating a memory shortage (TBC):
> > https://launchpadlibrarian.net/253916410/apport-retrace.log
> > 
> > Known Todos:
> > - I want to track it down more, and will try to come up with a non
> > openvswitch based looping testcase that might show it as well to simplify
> > debugging.
> > - in use were Openvswitch-dpdk 2.5 and DPDK 2.2; Retest with DPDK 16.04 and
> > Openvswitch master is planned.
> > 
> > I will go on debugging this and let you know, but I wanted to give a heads
> > up to everyone.
> 
> Thanks for the report.
> 
> > In case this is a known issue for some of you please let me know.
> 
> Yeah, it might be. I'm wondering that virtio_net struct is not freed.
> It will be freed only (if I'm not mistaken) when guest quits, by far.

Would you try following diff and to see if it fix your issue?

        --yliu

---
 lib/librte_vhost/vhost_user/vhost-net-user.c | 6 ++++++
 lib/librte_vhost/vhost_user/vhost-net-user.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c 
b/lib/librte_vhost/vhost_user/vhost-net-user.c
index df2bd64..8f7ebd7 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.c
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
@@ -309,6 +309,7 @@ vserver_new_vq_conn(int fd, void *dat, __rte_unused int 
*remove)
        }

        vdev_ctx.fh = fh;
+       vserver->fh = fh;
        size = strnlen(vserver->path, PATH_MAX);
        vhost_set_ifname(vdev_ctx, vserver->path,
                size);
@@ -501,6 +502,11 @@ rte_vhost_driver_unregister(const char *path)

        for (i = 0; i < g_vhost_server.vserver_cnt; i++) {
                if (!strcmp(g_vhost_server.server[i]->path, path)) {
+                       struct vhost_device_ctx ctx;
+
+                       ctx.fh = g_vhost_server.server[i]->fh;
+                       vhost_destroy_device(ctx);
+
                        fdset_del(&g_vhost_server.fdset,
                                g_vhost_server.server[i]->listenfd);

diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.h 
b/lib/librte_vhost/vhost_user/vhost-net-user.h
index e3bb413..7cf21db 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.h
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.h
@@ -43,6 +43,7 @@
 struct vhost_server {
        char *path; /**< The path the uds is bind to. */
        int listenfd;     /**< The listener sockfd. */
+       uint32_t fh;
 };

 /* refer to hw/virtio/vhost-user.c */
-- 
1.9.3